Chapter 3 [compatibility mode]

Science

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  • Chapter Chapter 33 البــاب الثالــثالبــاب الثالــث The Molecules of Cells الجزيئات الخلوية Copyright © 2009 Pearson Education, Inc. PowerPoint Lectures for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Lecture by Richard L. Myers Translated by Nabih Baeshen
  • Lactose intolerance People who are Lactose Intolerance can digest food that contain lactose (such as ice cream) by taking pills that contain the enzyme lactase
  • Introduction: Got Lactose? � Most of the world’s population cannot digest milk-based foods � They are lactose intolerant, because they lack the enzyme lactaseenzyme lactase � This illustrates the importance of biological molecules, such as lactase, to functioning living organisms Copyright © 2009 Pearson Education, Inc. Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)
  • INTRODUCTION TO ORGANIC COMPOUNDS (Molecules) Copyright © 2009 Pearson Education, Inc.
  • 3.1 Life’s molecular diversity is based on the properties of carbon � Diverse molecules found in cells are composed of carboncarboncarboncarbon bonded to other elements – Carbon-based molecules are called organic organic organic organic compoundscompoundscompoundscompounds – By sharing electrons, carbon can bond to four other atoms – By doing so, it can branch in up to four directions Copyright © 2009 Pearson Education, Inc.
  • 3.1 Life’s molecular diversity is based on the properties of carbon � Methane (CH4) is one of the simplest organic compounds – Four covalent bonds link four hydrogen atoms to the carbon atom – Four covalent bonds link four hydrogen atoms to the carbon atom – Each of the four lines in the formula for methane represents a pair of shared electrons Copyright © 2009 Pearson Education, Inc.
  • Structural formula Ball-and-stick model Space-filling model Three representations of methane (CH4) Methane The four single bonds of carbon point to the corners of a tetrahedron.
  • 3.1 Life’s molecular diversity is based on the properties of carbon �Methane and other compounds composed of only carbon and hydrogen are called hydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbons –Carbon atoms, with attached hydrogens, can bond together in chains of various lengths Copyright © 2009 Pearson Education, Inc. Petroleum
  • � A chain of carbon atoms is called a carbon a carbon a carbon a carbon skeletonskeletonskeletonskeleton – Carbon skeletons can be branched or unbranched 3.1 Life’s molecular diversity is based on the properties of carbon – Therefore, different compounds with the same same same same molecular formula molecular formula molecular formula molecular formula can be produced – These structures are called isomers Copyright © 2009 Pearson Education, Inc.
  • Carbon skeletons vary in length. تتباين أطوال ھياكل الكربون: الطول Branching. Skeletons may be unbranched or branched. قد تكون الھياكل متفرعة أو غير متفرعة: التفرع Butane بيوتان Isobutane أيزوبيتان Propane بروبانEthane إيثان Length. Variations in carbon skeletons Double bonds. 2-Butene بيوتان - 2 Skeletons may have double bonds, which can vary in location. قد تحتوي الھياكل على روابط ثنائية تتنوع في مواقعھا: الروابط الثنائية Cyclohexane ھكسان حلقي 1-Butene بيوتان - 1 Benzene بنزين Skeletons may be arranged in rings. قد تنتظم الھياكل في حلقات: الحلقات Rings.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � An organic compound has unique properties that depend upon : – The size and shape of the molecule– The size and shape of the molecule – The groups of atoms (functional groups) attached to it � A functional groupfunctional groupfunctional groupfunctional group affects a biological molecule’s function in a characteristic way Copyright © 2009 Pearson Education, Inc.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � Compounds containing functional groups are hydrophilichydrophilichydrophilichydrophilic (water-loving) – This means that they are soluble – This means that they are soluble in water, which is a necessary prerequisite for their roles in water-based life. Copyright © 2009 Pearson Education, Inc.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � The functional groups are وهذه هي المجاميع الوظيفية 1.1.1.1. HydroxylHydroxylHydroxylHydroxyl groupgroupgroupgroup—consists of a hydrogenhydrogenhydrogenhydrogen bonded to an oxygenoxygenoxygenoxygen 2.2.2.2. CarbonylCarbonylCarbonylCarbonyl groupgroupgroupgroup—a carboncarboncarboncarbon linked by a double bond to an oxygen atom 3.3.3.3. CarboxylCarboxylCarboxylCarboxyl groupgroupgroupgroup—consists of a carboncarboncarboncarbon bonded to a hydroxyl group hydroxyl group hydroxyl group hydroxyl group and double-bonded to an oxygenoxygenoxygenoxygen 4.4.4.4. AminoAminoAminoAmino groupgroupgroupgroup—composed of a nitrogennitrogennitrogennitrogen bonded to two two two two hydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeleton 5.5.5.5. PhosphatePhosphatePhosphatePhosphate groupgroupgroupgroup—consists of a phosphorus atom bonded to four oxygen four oxygen four oxygen four oxygen atoms Copyright © 2009 Pearson Education, Inc.
  • المجاميع الوظيفية للمركبات العضوية أمثلة مجموعة ھيدروكسيل المجموعة الوظيفية كحول مجموعة كربونيل الدھايد كيتون مجموعة كاربوكسيل حمض كربوكسيلي حمض كربوكسيليحمض كربوكسيلي مؤين حمض كربوكسيلي مؤين مجموعة أمين أمين أمين مؤين مجموعة فوسفات (ATP)فوسفات عضوي ادينوسين مجموعة ميثيل مركب ميثيلي
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � There are four classes of biological molecules 1.1.1.1. CarbohydratesCarbohydratesCarbohydratesCarbohydratesاااا 2.2.2.2. ProteinsProteinsProteinsProteins 3.3.3.3. LipidsLipidsLipidsLipids 4.4.4.4. Nucleic acidsNucleic acidsNucleic acidsNucleic acids Copyright © 2009 Pearson Education, Inc.
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � The four classes of biological molecules contain very large molecules – They are often called macromoleculesmacromoleculesmacromoleculesmacromolecules because of their large size – They are also called polymerspolymerspolymerspolymers because they are made from identical building blocks strung together – The building blocks are called monomersmonomersmonomersmonomers Copyright © 2009 Pearson Education, Inc.
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � Monomers Monomers Monomers Monomers are linked together to form polymerspolymerspolymerspolymers through dehydration reactionsdehydration reactionsdehydration reactionsdehydration reactions, which remove water � Polymers are broken apart by hydrolysis,hydrolysis,hydrolysis,hydrolysis, the � Polymers are broken apart by hydrolysis,hydrolysis,hydrolysis,hydrolysis, the addition of water � All biological reactions of this sort are mediated by enzymes, which speed up chemical reactions in cells Copyright © 2009 Pearson Education, Inc.
  • Unlinked Monomer Short polymer Dehydration Dehydration reactions build a polymer chain Longer polymer Dehydration Reaction
  • Hydrolysis breaks a polymer chain Hydrolysis
  • CARBOHYDRATESCARBOHYDRATESCARBOHYDRATESCARBOHYDRATES Copyright © 2009 Pearson Education, Inc.
  • 3.4 Monosaccharides are the simplest carbohydrates السكريات ا2حادية ھي أبسط الكربوھيدرات � CarbohydratesCarbohydratesCarbohydratesCarbohydrates range from small sugar molecules (monomers) to large polysaccharides – Sugar monomers are monosaccharidesmonosaccharidesmonosaccharidesmonosaccharides, such as glucose glucose glucose glucose monosaccharidesmonosaccharidesmonosaccharidesmonosaccharides, such as glucose glucose glucose glucose and fructosefructosefructosefructose – These can be hooked together to form the polysaccharidespolysaccharidespolysaccharidespolysaccharides Copyright © 2009 Pearson Education, Inc.
  • 3.4 Monosaccharides are the simplest carbohydrates � The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides vary in lengthvary in lengthvary in lengthvary in length – Glucose and fructose are six carbons long – Others have three to seven carbon atoms � Monosaccharides are the main fuels Monosaccharides are the main fuels Monosaccharides are the main fuels Monosaccharides are the main fuels (energy) (energy) (energy) (energy) for cellular for cellular for cellular for cellular workworkworkwork – Monosaccharides are also used as raw materials to manufacture other organic molecules Copyright © 2009 Pearson Education, Inc.
  • Structures of glucose and fructose Glucoseا (an aldose ) Fructose (a ketose )
  • Three representations of the ring form of glucose Structural Formula ا Abbreviated Structure Simplified Structure
  • 3.5 Cells link two single sugars to form disaccharides � Two monosaccharides (monomers) can bond to form a disaccharidedisaccharidedisaccharidedisaccharide in a dehydration reaction – An example is a glucoseglucoseglucoseglucose monomer – An example is a glucoseglucoseglucoseglucose monomer bonding to a fructosefructosefructosefructose monomer to form sucrosesucrosesucrosesucrose, a common disaccharide Copyright © 2009 Pearson Education, Inc.
  • Glucose Glucose Maltose Disaccharide formation by a dehydration reaction
  • 3.7 Polysaccharides are long chains of sugar units � StarchStarchStarchStarch is a storage polysaccharide composed of glucose monomers and found in plants � GlycogenGlycogenGlycogenGlycogen is a storage polysaccharide composed of glucose, which is hydrolyzed by animals when glucose is neededglucose is needed � CellulosCellulosCellulosCelluloseeee is a polymer of glucose that forms plant cell walls � ChitinChitinChitinChitin is a polysaccharide used by insects and crustaceans to build an exoskeleton Copyright © 2009 Pearson Education, Inc.
  • Starch granules in potato tuber cells Glycogen granules in muscle tissue Glucose Monomer GLYCOGEN STARCH Polysaccharides Cellulose fibrils in a plant cell wall Cellulose Molecules CELLULOSE Hydrogen bonds روابط ھيدروجينية
  • LIPIDS Copyright © 2009 Pearson Education, Inc. SteroidsPhospholipids True Fats
  • 3.8 Fats are lipids that are mostly energy-storage molecules � LipidsLipidsLipidsLipids are water insoluble (hydrophobichydrophobichydrophobichydrophobic, or water fearing) compounds that are important in energy storage – They contain twice as much energyenergyenergyenergy as a polysaccharide � FatsFatsFatsFats are lipids made from glycerol and fatty acids Copyright © 2009 Pearson Education, Inc.
  • 3.8 Fats are lipids that are mostly energy-storage molecules � Fatty acids link to glycerol by a Fatty acids link to glycerol by a Fatty acids link to glycerol by a Fatty acids link to glycerol by a dehydration reactiondehydration reactiondehydration reactiondehydration reaction – A fat contains one glycerol linked to three fatty acids – A fat contains one glycerol linked to three fatty acids – Fats are often called triglycerides because of their structure Copyright © 2009 Pearson Education, Inc.
  • Fatty acid Glycerol Fatty acid A dehydration reaction linking a fatty acid to glycerol
  • A fat molecule made from glycerol and three fatty acids
  • 3.8 Fats are lipids that are mostly energy-storage molecules � Some fatty acids contain double bondsSome fatty acids contain double bondsSome fatty acids contain double bondsSome fatty acids contain double bonds – This causes links or bends in the carbon chain because the maximum number of hydrogen atoms cannot bond to the carbons at the double bondbond – These compounds are called unsaturatedunsaturatedunsaturatedunsaturated fats fats fats fats because they have fewer than the maximum number of hydrogens – Fats with the maximum number of hydrogensare called saturated fatssaturated fatssaturated fatssaturated fats Copyright © 2009 Pearson Education, Inc.
  • 3.9 Phospholipids and steroids are important lipids with a variety of functions � PhospholipidsPhospholipidsPhospholipidsPhospholipids are structurally similar to fats and are an are structurally similar to fats and are an are structurally similar to fats and are an are structurally similar to fats and are an important component of all cellsimportant component of all cellsimportant component of all cellsimportant component of all cells 1. For example, they are a major part of cell membranes, in which they cluster into a bilayerof phospholipids 2. The hydrophilichydrophilichydrophilichydrophilic heads are in contact with the water of the environment and the internal part of the cell 3. The hydrophobichydrophobichydrophobichydrophobic tails band in the center of the bilayer Copyright © 2009 Pearson Education, Inc.
  • Water Hydrophobic Hydrophilic heads رؤس محبة للماء Section of a phospholipid membrane Cell external surface Hydrophobic tails ذيول كارھة للماء Water السطح الداخلي للخلية Cell internal surface
  • 3.9 Phospholipids and steroids are important lipids with a variety of functions � Steroids Steroids Steroids Steroids are lipids composed of fused ring are lipids composed of fused ring are lipids composed of fused ring are lipids composed of fused ring structuresstructuresstructuresstructures – CholesterolCholesterolCholesterolCholesterol is an example of a steroid that plays a significant role in steroid that plays a significant role in the structure of the cell membrane – In addition, cholesterol is the compound from which we synthesize sex hormones Copyright © 2009 Pearson Education, Inc.
  • PROTEINS Copyright © 2009 Pearson Education, Inc.
  • 3.11 Proteins are essential to the structures and functions of life � A proteinproteinproteinprotein is a polymer built from various combinations of 20 amino acid monomers – Proteins have unique structures that are directly related to their functionsare directly related to their functions – EnzymesEnzymesEnzymesEnzymes, proteins that serve as metabolic catalysts, regulate the chemical reactions within cells Copyright © 2009 Pearson Education, Inc.
  • 3.11 Proteins are essential to the structures and functions of life ا � Structural Structural Structural Structural proteins provide associations between body parts and contractilecontractilecontractilecontractile proteins are found within muscle � DefensiveDefensiveDefensiveDefensive proteins include antibodies of the � DefensiveDefensiveDefensiveDefensive proteins include antibodies of the immune system, and signalsignalsignalsignal proteins are best exemplified by the hormones � ReceptorReceptorReceptorReceptor proteins serve as antenna for outside signals, and transporttransporttransporttransport proteins carry oxygen Copyright © 2009 Pearson Education, Inc.
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acidsAmino acidsAmino acidsAmino acids, the building blocks of proteins, have an amino group and a carboxyl group – Both of these are covalently bonded covalently bonded covalently bonded covalently bonded to a – Both of these are covalently bonded covalently bonded covalently bonded covalently bonded to a central carbon atom – Also bonded to the central carbon is a hydrogen atom hydrogen atom hydrogen atom hydrogen atom and some other chemical chemical chemical chemical group symbolized by Rgroup symbolized by Rgroup symbolized by Rgroup symbolized by R Copyright © 2009 Pearson Education, Inc.
  • General structure of an amino acid Carboxyl group Amino Group م
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acids are classified as hydrophobic hydrophobic hydrophobic hydrophobic or hydrophilichydrophilichydrophilichydrophilic – Some amino acids have a nonpolar R group – Some amino acids have a nonpolar R group and are hydrophobichydrophobichydrophobichydrophobic – Others have a polar R a polar R a polar R a polar R group and are hydrophilichydrophilichydrophilichydrophilic, which means they easily dissolve in aqueous solutions Copyright © 2009 Pearson Education, Inc.
  • Examples of amino acids with hydrophobic and hydrophilic R groups Leucine (Leu) Hydrophobic Serine (Ser) ا Hydrophilic Aspartic acid (Asp)
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acid monomersmonomersmonomersmonomers are linked together to form polymericpolymericpolymericpolymeric proteins – This is accomplished by an enzymeenzymeenzymeenzyme----mediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reaction – This links the carboxyl group carboxyl group carboxyl group carboxyl group of one amino acid to the amino group amino group amino group amino group of the next amino acid – The covalentcovalentcovalentcovalent linkage resulting is called a peptide bonda peptide bonda peptide bonda peptide bond Copyright © 2009 Pearson Education, Inc.
  • Peptide bond Dehydration Reaction Peptide bond formation Carboxyl group Amino group Dipeptide ثنائي الببتيد Amino acid Amino acid
  • 3.13 A protein’s specific shape determines its function � A polypeptide chain contains hundreds or thousands of amino acids linked by peptide bonds – The amino acid sequence causes the – The amino acid sequence causes the polypeptide to assume a particular shape – The shape of a protein determines its specific function Copyright © 2009 Pearson Education, Inc.
  • Groove Space-filling model of lysozyme
  • 3.14 A protein’s shape depends on four levels of structure � A protein can have four levels of structure – Primary structurePrimary structurePrimary structurePrimary structure – Secondary structureSecondary structureSecondary structureSecondary structure – Secondary structureSecondary structureSecondary structureSecondary structure – Tertiary structureTertiary structureTertiary structureTertiary structure – Quaternary structureQuaternary structureQuaternary structureQuaternary structure Copyright © 2009 Pearson Education, Inc.
  • 3.14 A protein’s shape depends on four levels of structure � The primary structureprimary structureprimary structureprimary structure of a protein is its unique amino acid sequence – The correct amino acid sequence is determined by the cell’s genetic determined by the cell’s genetic information – The slightest change in this sequence affects the protein’s ability to function Copyright © 2009 Pearson Education, Inc.
  • Amino acids Primary structureأحماض أمينية التركيب ا7ولي
  • 3.14 A protein’s shape depends on four levels of structure � Protein secondary structuresecondary structuresecondary structuresecondary structure results from coiling or folding of the polypeptide – Coiling results in a helical structure called an alpha helixalpha helixalpha helixalpha helix – Folding may lead to a structure called a pleated sheetpleated sheetpleated sheetpleated sheet – Coiling and folding result from hydrogen bonding hydrogen bonding hydrogen bonding hydrogen bonding between certain areas of the polypeptide chain Copyright © 2009 Pearson Education, Inc.
  • Amino acids Hydrogen bond Alpha helix Secondary structure Pleated sheet
  • 3.14 A protein’s shape depends on four levels of structure � The overall three-dimensional shape of a protein is called its tertiary structuretertiary structuretertiary structuretertiary structure – Tertiary structure generally results from interactions between the R groups of the interactions between the R groups of the various amino acids – Disulfide bridges Disulfide bridges Disulfide bridges Disulfide bridges are covalentcovalentcovalentcovalent bonds that further strengthen the protein’s shape Copyright © 2009 Pearson Education, Inc.
  • Globular Polypeptide (single subunit(single subunit of transthyretin) Tertiary structure
  • 3.14 A protein’s shape depends on four levels of structure � Two or more polypeptide chains Two or more polypeptide chains Two or more polypeptide chains Two or more polypeptide chains (subunits) associate providing (subunits) associate providing (subunits) associate providing (subunits) associate providing quaternary quaternary quaternary quaternary structurestructurestructurestructure – Collagen is an example of a protein with quaternary structurewith quaternary structure – Its triple helix gives great strength to connective tissue, bone, tendons, and ligaments Copyright © 2009 Pearson Education, Inc.
  • PolypeptidePolypeptidePolypeptidePolypeptide chain (alpha helix)chain (alpha helix)chain (alpha helix)chain (alpha helix) Collagen is a fibrous protein with helical subunits Interwind into a larger triple helix, this Collagen fiberCollagen fiberCollagen fiberCollagen fiber helix, this arrangement gives the long fibers great strength Triple helix
  • Transthyretin, with four identical globular polypeptide subunits Quaternary structure Transthyretin: A plasma protein consisting of 127 amino acids that binds retinol and thyroxine
  • Four Levels of Protein Structure أربع مستويات من تركيب البروتين Primary structurePrimary structurePrimary structurePrimary structure Amino acids أحماض أمينية Hydrogen bond روابط ھيدروجينية Secondary structureSecondary structureSecondary structureSecondary structure Pleated sheet صحيفة مطوية Alpha helix حلزون ألفا Transthyretin, with four identical globular polypeptide subunits الترانسثيريتين بأربع من الوحدات الفرعية الكروية المتماثلة من متعدد البيبتيدات Quaternary structureQuaternary structureQuaternary structureQuaternary structure حلزون ألفاصحيفة مطوية Tertiary structureTertiary structureTertiary structureTertiary structure Globular Polypeptide (single subunit of transthyretin)
  • 3.13 A protein’s specific shape determines its function � If for some reason a protein’s shape is altered, it can no longer function – DenaturationDenaturationDenaturationDenaturation will cause polypeptide chains to unravel and lose their shape and, thus, their functionfunction – Proteins can be denatured by changes in salt salt salt salt concentration and pHconcentration and pHconcentration and pHconcentration and pH Copyright © 2009 Pearson Education, Inc.
  • NUCLEIC ACIDS Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � DNADNADNADNA (deoxyribonucleic aciddeoxyribonucleic aciddeoxyribonucleic aciddeoxyribonucleic acid) and RNARNARNARNA (ribonucleic ribonucleic ribonucleic ribonucleic acidacidacidacid) are composed of monomers called nucleotidesnucleotidesnucleotidesnucleotides – Nucleotides have three parts – A fiveA fiveA fiveA five----carbon sugar carbon sugar carbon sugar carbon sugar called ribose in RNA and deoxyribose in DNA – A phosphate groupA phosphate groupA phosphate groupA phosphate group – A nitrogenous base Copyright © 2009 Pearson Education, Inc.
  • Nitrogenous nucleotide, consisting of a phosphate group, sugar, and a nitrogenous base Phosphate Group Nitrogenous base (adenine) Sugar
  • Dehydration Short polymer Monomer Hydrolysis Longer polymer
  • Nucleotide Sugar-phosphate backbone Part of a polynucleotide
  • Base pair DNA double helix
  • � DNA nitrogenous bases are adenine (A), thymine (T), cytosine (C), and guanine (G) – RNA also has A, C, and G, but 3.16 Nucleic acids are information-rich polymers of nucleotides – RNA also has A, C, and G, but instead of T, it has uracil (U) Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � Two polynucleotide strands wrap around each other to form a DNA double helixdouble helixdouble helixdouble helix – The two strands are associated because particular bases always hydrogen bond to one anotherone another – A pairs with T, and C pairs with G, producing base pairsbase pairsbase pairsbase pairs � RNA is usually a single polynucleotide strand Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � A particular nucleotide sequence that can instruct the formation of a polypeptide is called a genegenegenegene – Most DNA molecules consist of millions of base pairs and, consequently, many base pairs and, consequently, many genes – These genes, many of which are unique to the species, determine the structure of proteins and, thus, life’s structures and functions Copyright © 2009 Pearson Education, Inc.
  • 3.17 EVOLUTION CONNECTION: Lactose tolerance is a recent event in human evolution � Mutations Mutations Mutations Mutations are alterations in bases or the sequence of are alterations in bases or the sequence of are alterations in bases or the sequence of are alterations in bases or the sequence of bases in DNAbases in DNAbases in DNAbases in DNA � Lactose tolerance is the result of mutationsLactose tolerance is the result of mutationsLactose tolerance is the result of mutationsLactose tolerance is the result of mutations – In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization is turned off in adulthoodis turned off in adulthoodis turned off in adulthoodis turned off in adulthood – In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization is turned off in adulthoodis turned off in adulthoodis turned off in adulthoodis turned off in adulthood – Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented the gene from turning offthe gene from turning offthe gene from turning offthe gene from turning off – This is an excellent example of human evolutionThis is an excellent example of human evolutionThis is an excellent example of human evolutionThis is an excellent example of human evolution Copyright © 2009 Pearson Education, Inc.
  • You should now be able to ينبغي أن تكون قادراً ا;ن على فعل ما يلي 1. Discuss the importance of carbon to life’s molecular diversity ناقش أهمية الكربون في تنوع الجزيئات الحيوية. 1 2. Describe the chemical groups that are important to life صف المجاميع الكيميائية الهامة للحياة. 2 3. Explain how a cell can make a variety of large molecules from a small set of molecules اشرح كيفية تصنيع الخلية للعديد من الجزيئات الكبيرة من مجموعة صغيرة من . 3 الجزيئاتاشرح كيفية تصنيع الخلية للعديد من الجزيئات الكبيرة من مجموعة صغيرة من . 3 4. Define monosaccharides, disaccharides, and polysaccharides and explain their functions عرف السكاكر األحادية والثنائية والعديدة مع شرح وظائفها. 4 5. Define lipids, phospholipids, and steroids and explain their functions عرف اللبيدات والدهون الفسفورية واالسترويدات مع شرح وظائفها. 5 Copyright © 2009 Pearson Education, Inc.
  • You should now be able to ينبغي أن تكون قادراً ا;ن على فعل ما يلي 6. Describe the chemical structure of proteins and their importance to cells صف التركيب الكيميائي للبروتينات وأهميتها للخاليا. 6 7. Describe the chemical structure of nucleic acids and how they relate to inheritanceand how they relate to inheritance صف التركيب الكيميائي لألحماض النووية وعالقتها بالوراثة. 7 Copyright © 2009 Pearson Education, Inc.
  • Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Organic Compounds (Molecules) العضوية) الجزيئات(مدخل للمركبات Organic Compounds بالمركبات العضويةتسمى الجزيئات التي أساسھا ذرة الكربون Hydrocarbons يسمى كل من الميثان والمركبات المؤلفة من كربون وھيدروجين فقط بالھايدروكربونات Carbon Skeleton تسمسى سلسلة ذرات الكربون بالھيكل الكربوني Carbon Skeletons Can Be Branched Or Unbranched قد يتفرع الھيكل الكربوني أو 9 يتفرع Therefore, Different Compounds With The لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية Same Molecular Formula Can Be Produced لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية These Structures Are Called Isomers تعرف ھذه التراكيب بالنظائر Functional Group Affects A Biological Molecule’s Function In A Characteristic Way تؤثر المجموعة الوظيفية في وظيفة الجزيئ الحيوي بطريقة مميزة Hydrophilic (Water-Loving) المركبات المحتوية على مجاميع وظيفية تكون محبة للماء This Means That They Are Soluble In Water, Which Is A Necessary Prerequisite For Their Roles In Water-Based Life يعني ھذا أنھا تذوب في الماء وھذا متطلب ضروري للقيام بوظائفھا الحيوية المعتمدة على الماء Hydroxyl Group—Consists Of A Hydrogen Bonded To An Oxygen تتكون من ھيدروجين مرتبط بأوكسجين–الھيدروكسيلمجموعة
  • Carbonyl Group—A Carbon Linked By A Double Bond To An Oxygen Atom كربون متصل بذرة أوكسجين برابطة ثنائية–الكربونيلمجموعة Carboxyl Group—Consists Of A Carbon Bonded To A Hydroxyl Group And Double- Bonded To An Oxygen تتألف من كربون مرتبط بمجموعة –كربوكسيلمجموعة كما وترتبط برابطة ثنائية باRوكسجين الھيدروكسيل Amino Group—Composed Of A Nitrogen Bonded To Two Hydrogen Atoms And A Carbon Skeleton مكونة من نيتروجين مرتبط بذرتي ھيدروجين –مجموعة أمين وھيكل كربوني Phosphate Group—Consists Of A Phosphorus تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Phosphate Group—Consists Of A Phosphorus Atom Bonded To Four Oxygen Atoms تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات أوكسجين Biological Molecules ھناك أربعة أصناف من الجزيئات الحيوية Carbohydrates الكربوھيدرات Proteins البروتينات Lipids الدھون(اللبيدات( Nucleic Acids حماض النوويةRا Macromolecules Because Of Their Large Size تسمى عادة بالجزيئات الكبيرة لحجمھا الكبير They Are Made From Identical Building Blocks Strung Together Rنھا مكونة من وحدات بنائية متماثلة بالبوليميراتتسمى أيضاً متماسكة بقوة
  • The Building Blocks Are Called Monomers بالمونيميراتتسمى وحدات البناء Dehydration Reactions, Which Remove Water بتفاعYت نزع الماء بوليميراتلتكون ببعضھا المونيميراتترتبط Polymers Are Broken Apart By Hydrolysis, The Addition Of Water )بإضافة الماء( الحلمأةأو بالتميؤ البوليميراتتنحل All Biological Reactions Of This Sort Are Mediated By Enzymes, Which Speed Up Chemical Reactions In Cells كل ھذه العمليات الحيوية من ھذا النوع تتوسط فيھا ا]نزيمات التي تسرع من التفاعYت الكيميائية في الخYيا Dehydration Reaction تفاعل نزع الماء Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Dehydration Reaction تفاعل نزع الماء Hydrolysis الحلمأةأو التميؤ Monosaccharides, Such As Glucose And Fructose سكر مثل الجلوكوز مونيميراتالسكريات اRحادية عبارة عن والفركتوز Disaccharide In A Dehydration Reaction البعض ليكونا ببعضھما) مونيمران(يمكن أن يرتبط سكران أحاديان سكراً ثنائياً بتفاعل نزع الماء An Example Is A Glucose Monomer Bonding To A Fructose Monomer To Form Sucrose, A Common Disaccharide لتكوين الفركتوز بمونيمرالجلوكوز مونيمر إرتباطمثال ذلك ھو )سكر ثنائي شائع( السكروز
  • Starch Is A Storage Polysaccharide Composed Of Glucose Monomers And Found In Plants جلوكوز مونيميراتتخزيني ويتكون من سكرمتعددالنشا عبارة عن ويوجد في النبات Glycogen Is A Storage Polysaccharide Composed Of Glucose, Which Is Hydrolyzed By Animals When Glucose Is Needed تخزيني ويتكون من سكرمتعددعن الحيوانيعبارةأو النشا الجYيكوجين عند الحاجة إلى الجلوكوز الجYيكوجينالجلوكوز ، وتحلل الحيوانات Cellulose Is A Polymer Of Glucose That Forms Plant Cell Walls جلوكوزي يكون جدر الخYيا في النباتات بوليميرعبارة عن السيليلوز Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Forms Plant Cell Walls Chitin Is A Polysaccharide Used By Insects And Crustaceans To Build An Exoskeleton عبارة عن سكر متعدد تستخدمه الحشرات والقشريات لبناء الكايتين ھياكلھا الخارجية Lipids Are Water Insoluble (Hydrophobic, Or Water Fearing) Compounds That Are Important In Energy Storage ، وھي ھامة في ) كارھة للماء(ھي مركبات 9 تذوب في الماء اللبيدات تخزين الطاقة They Contain Twice As Much Energy As A Polysaccharide المتعددة السكاكرتحتوي على ضعف الطاقة الموجودة في Fats Are Lipids Made From Glycerol And Fatty Acids نوع من اللبيدات مكونة من ) السمن والزبدة والزيت(الدھون جليسيرول وأحماض دھنية Unsaturated Fats Because They Have Fewer Than The Maximum Number Of Hydrogens تسمى ھذه المركبات بالدھون غير المشبعة Rنھا تحتوى على عدد أقل من العدد الكلي للھيدروجين
  • Fats With The Maximum Number Of Hydrogens Are Called Saturated Fats تسمى الدھون المحتوية على العدد الكلي للھيدروجين بالدھون المشبعة )الكربون ذراتروابط ثنائية بين بھا9 يوجد ( Phospholipids Are Structurally Similar To Fats And Are An Important Component Of All Cells الفسفورية الدھون في تركيبھا وھي من المكونات اللبيداتتشابه اRساسية للخلية For Example, They Are A Major Part Of Cell Membranes, In Which They Cluster Into A Bilayer Of Phospholipids على سبيل المثال ھي مكون ھام لhغشية الخلوية حيث تتجمع على ھيئة طبقتين من الدھون الفسفورية Steroids Are Lipids Composed Of Fused Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Steroids Are Lipids Composed Of Fused Ring Structures عبارة عن دھون مكونة من حلقات تركيبية متداخلة اRسترويدات Cholesterol Is An Example Of A Steroid That Plays A Significant Role In The Structure Of The Cell Membrane التي تلعب دوراً ھاماً في تركيب لYسترويداتھو مثال الكوليسترول غشاء الخلية In Addition, Cholesterol Is The Compound From Which We Synthesize Sex Hormones ھرموناتنا بهھو المركب الذي نبني الكوليسترولبا]ضافة لذلك فإن الجنسية Anabolic Steroids Are Synthetic Variants Of Testosterone That Can Cause A Buildup Of Muscle And Bone Mass البنائي عبارة عن توليفة صناعية من اRيض سترويدات والتي تؤدي لبناء الكتلة العضلية ) الذكورة ھرمونات( التيستيسترونات والعظمية Protein Is A Polymer Built From Various Combinations Of 20 Amino Acid Monomers مونيمراتمن 20يبنى من توافيق بين بوليمرالبروتين عبارة عن اRمينيةاRحماض
  • Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Organic Compounds (Molecules) العضوية) الجزيئات(مدخل للمركبات Organic Compounds بالمركبات العضويةتسمى الجزيئات التي أساسھا ذرة الكربون Hydrocarbons يسمى كل من الميثان والمركبات المؤلفة من كربون وھيدروجين فقط بالھايدروكربونات Carbon Skeleton تسمسى سلسلة ذرات الكربون بالھيكل الكربوني Carbon Skeletons Can Be Branched Or Unbranched قد يتفرع الھيكل الكربوني أو 9 يتفرع Therefore, Different Compounds With The لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية Same Molecular Formula Can Be Produced لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية These Structures Are Called Isomers تعرف ھذه التراكيب بالنظائر Functional Group Affects A Biological Molecule’s Function In A Characteristic Way تؤثر المجموعة الوظيفية في وظيفة الجزيئ الحيوي بطريقة مميزة Hydrophilic (Water-Loving) المركبات المحتوية على مجاميع وظيفية تكون محبة للماء This Means That They Are Soluble In Water, Which Is A Necessary Prerequisite For Their Roles In Water-Based Life يعني ھذا أنھا تذوب في الماء وھذا متطلب ضروري للقيام بوظائفھا الحيوية المعتمدة على الماء Hydroxyl Group—Consists Of A Hydrogen Bonded To An Oxygen تتكون من ھيدروجين مرتبط بأوكسجين–الھيدروكسيلمجموعة
  • Carbonyl Group—A Carbon Linked By A Double Bond To An Oxygen Atom كربون متصل بذرة أوكسجين برابطة ثنائية–الكربونيلمجموعة Carboxyl Group—Consists Of A Carbon Bonded To A Hydroxyl Group And Double- Bonded To An Oxygen تتألف من كربون مرتبط بمجموعة –كربوكسيلمجموعة كما وترتبط برابطة ثنائية باRوكسجين الھيدروكسيل Amino Group—Composed Of A Nitrogen Bonded To Two Hydrogen Atoms And A Carbon Skeleton مكونة من نيتروجين مرتبط بذرتي ھيدروجين –مجموعة أمين وھيكل كربوني Phosphate Group—Consists Of A Phosphorus تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Phosphate Group—Consists Of A Phosphorus Atom Bonded To Four Oxygen Atoms تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات أوكسجين Biological Molecules ھناك أربعة أصناف من الجزيئات الحيوية Carbohydrates الكربوھيدرات Proteins البروتينات Lipids الدھون(اللبيدات( Nucleic Acids حماض النوويةRا Macromolecules Because Of Their Large Size تسمى عادة بالجزيئات الكبيرة لحجمھا الكبير They Are Made From Identical Building Blocks Strung Together Rنھا مكونة من وحدات بنائية متماثلة بالبوليميراتتسمى أيضاً متماسكة بقوة
  • The Building Blocks Are Called Monomers بالمونيميراتتسمى وحدات البناء Dehydration Reactions, Which Remove Water بتفاعYت نزع الماء بوليميراتلتكون ببعضھا المونيميراتترتبط Polymers Are Broken Apart By Hydrolysis, The Addition Of Water )بإضافة الماء( الحلمأةأو بالتميؤ البوليميراتتنحل All Biological Reactions Of This Sort Are Mediated By Enzymes, Which Speed Up Chemical Reactions In Cells كل ھذه العمليات الحيوية من ھذا النوع تتوسط فيھا ا]نزيمات التي تسرع من التفاعYت الكيميائية في الخYيا Dehydration Reaction تفاعل نزع الماء Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Dehydration Reaction تفاعل نزع الماء Hydrolysis الحلمأةأو التميؤ Monosaccharides, Such As Glucose And Fructose سكر مثل الجلوكوز مونيميراتالسكريات اRحادية عبارة عن والفركتوز Disaccharide In A Dehydration Reaction البعض ليكونا ببعضھما) مونيمران(يمكن أن يرتبط سكران أحاديان سكراً ثنائياً بتفاعل نزع الماء An Example Is A Glucose Monomer Bonding To A Fructose Monomer To Form Sucrose, A Common Disaccharide لتكوين الفركتوز بمونيمرالجلوكوز مونيمر إرتباطمثال ذلك ھو )سكر ثنائي شائع( السكروز
  • Starch Is A Storage Polysaccharide Composed Of Glucose Monomers And Found In Plants جلوكوز مونيميراتتخزيني ويتكون من سكرمتعددالنشا عبارة عن ويوجد في النبات Glycogen Is A Storage Polysaccharide Composed Of Glucose, Which Is Hydrolyzed By Animals When Glucose Is Needed تخزيني ويتكون من سكرمتعددعن الحيوانيعبارةأو النشا الجYيكوجين عند الحاجة إلى الجلوكوز الجYيكوجينالجلوكوز ، وتحلل الحيوانات Cellulose Is A Polymer Of Glucose That Forms Plant Cell Walls جلوكوزي يكون جدر الخYيا في النباتات بوليميرعبارة عن السيليلوز Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Forms Plant Cell Walls Chitin Is A Polysaccharide Used By Insects And Crustaceans To Build An Exoskeleton عبارة عن سكر متعدد تستخدمه الحشرات والقشريات لبناء الكايتين ھياكلھا الخارجية Lipids Are Water Insoluble (Hydrophobic, Or Water Fearing) Compounds That Are Important In Energy Storage ، وھي ھامة في ) كارھة للماء(ھي مركبات 9 تذوب في الماء اللبيدات تخزين الطاقة They Contain Twice As Much Energy As A Polysaccharide المتعددة السكاكرتحتوي على ضعف الطاقة الموجودة في Fats Are Lipids Made From Glycerol And Fatty Acids نوع من اللبيدات مكونة من ) السمن والزبدة والزيت(الدھون جليسيرول وأحماض دھنية Unsaturated Fats Because They Have Fewer Than The Maximum Number Of Hydrogens تسمى ھذه المركبات بالدھون غير المشبعة Rنھا تحتوى على عدد أقل من العدد الكلي للھيدروجين
  • Fats With The Maximum Number Of Hydrogens Are Called Saturated Fats تسمى الدھون المحتوية على العدد الكلي للھيدروجين بالدھون المشبعة )الكربون ذراتروابط ثنائية بين بھا9 يوجد ( Phospholipids Are Structurally Similar To Fats And Are An Important Component Of All Cells الفسفورية الدھون في تركيبھا وھي من المكونات اللبيداتتشابه اRساسية للخلية For Example, They Are A Major Part Of Cell Membranes, In Which They Cluster Into A Bilayer Of Phospholipids على سبيل المثال ھي مكون ھام لhغشية الخلوية حيث تتجمع على ھيئة طبقتين من الدھون الفسفورية Steroids Are Lipids Composed Of Fused Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Steroids Are Lipids Composed Of Fused Ring Structures عبارة عن دھون مكونة من حلقات تركيبية متداخلة اRسترويدات Cholesterol Is An Example Of A Steroid That Plays A Significant Role In The Structure Of The Cell Membrane التي تلعب دوراً ھاماً في تركيب لYسترويداتھو مثال الكوليسترول غشاء الخلية In Addition, Cholesterol Is The Compound From Which We Synthesize Sex Hormones ھرموناتنا بهھو المركب الذي نبني الكوليسترولبا]ضافة لذلك فإن الجنسية Anabolic Steroids Are Synthetic Variants Of Testosterone That Can Cause A Buildup Of Muscle And Bone Mass البنائي عبارة عن توليفة صناعية من اRيض سترويدات والتي تؤدي لبناء الكتلة العضلية ) الذكورة ھرمونات( التيستيسترونات والعظمية Protein Is A Polymer Built From Various Combinations Of 20 Amino Acid Monomers مونيمراتمن 20يبنى من توافيق بين بوليمرالبروتين عبارة عن اRمينيةاRحماض
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  • Chapter Chapter 33 البــاب الثالــثالبــاب الثالــث The Molecules of Cells الجزيئات الخلوية Copyright © 2009 Pearson Education, Inc. PowerPoint Lectures for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Lecture by Richard L. Myers Translated by Nabih Baeshen
  • Lactose intolerance People who are Lactose Intolerance can digest food that contain lactose (such as ice cream) by taking pills that contain the enzyme lactase
  • Introduction: Got Lactose? � Most of the world’s population cannot digest milk-based foods � They are lactose intolerant, because they lack the enzyme lactaseenzyme lactase � This illustrates the importance of biological molecules, such as lactase, to functioning living organisms Copyright © 2009 Pearson Education, Inc. Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)Model of a milk digesting enzyme (Lactase)
  • INTRODUCTION TO ORGANIC COMPOUNDS (Molecules) Copyright © 2009 Pearson Education, Inc.
  • 3.1 Life’s molecular diversity is based on the properties of carbon � Diverse molecules found in cells are composed of carboncarboncarboncarbon bonded to other elements – Carbon-based molecules are called organic organic organic organic compoundscompoundscompoundscompounds – By sharing electrons, carbon can bond to four other atoms – By doing so, it can branch in up to four directions Copyright © 2009 Pearson Education, Inc.
  • 3.1 Life’s molecular diversity is based on the properties of carbon � Methane (CH4) is one of the simplest organic compounds – Four covalent bonds link four hydrogen atoms to the carbon atom – Four covalent bonds link four hydrogen atoms to the carbon atom – Each of the four lines in the formula for methane represents a pair of shared electrons Copyright © 2009 Pearson Education, Inc.
  • Structural formula Ball-and-stick model Space-filling model Three representations of methane (CH4) Methane The four single bonds of carbon point to the corners of a tetrahedron.
  • 3.1 Life’s molecular diversity is based on the properties of carbon �Methane and other compounds composed of only carbon and hydrogen are called hydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbonshydrocarbons –Carbon atoms, with attached hydrogens, can bond together in chains of various lengths Copyright © 2009 Pearson Education, Inc. Petroleum
  • � A chain of carbon atoms is called a carbon a carbon a carbon a carbon skeletonskeletonskeletonskeleton – Carbon skeletons can be branched or unbranched 3.1 Life’s molecular diversity is based on the properties of carbon – Therefore, different compounds with the same same same same molecular formula molecular formula molecular formula molecular formula can be produced – These structures are called isomers Copyright © 2009 Pearson Education, Inc.
  • Carbon skeletons vary in length. تتباين أطوال ھياكل الكربون: الطول Branching. Skeletons may be unbranched or branched. قد تكون الھياكل متفرعة أو غير متفرعة: التفرع Butane بيوتان Isobutane أيزوبيتان Propane بروبانEthane إيثان Length. Variations in carbon skeletons Double bonds. 2-Butene بيوتان - 2 Skeletons may have double bonds, which can vary in location. قد تحتوي الھياكل على روابط ثنائية تتنوع في مواقعھا: الروابط الثنائية Cyclohexane ھكسان حلقي 1-Butene بيوتان - 1 Benzene بنزين Skeletons may be arranged in rings. قد تنتظم الھياكل في حلقات: الحلقات Rings.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � An organic compound has unique properties that depend upon : – The size and shape of the molecule– The size and shape of the molecule – The groups of atoms (functional groups) attached to it � A functional groupfunctional groupfunctional groupfunctional group affects a biological molecule’s function in a characteristic way Copyright © 2009 Pearson Education, Inc.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � Compounds containing functional groups are hydrophilichydrophilichydrophilichydrophilic (water-loving) – This means that they are soluble – This means that they are soluble in water, which is a necessary prerequisite for their roles in water-based life. Copyright © 2009 Pearson Education, Inc.
  • 3.2 Characteristic chemical groups help determine the properties of organic compounds � The functional groups are وهذه هي المجاميع الوظيفية 1.1.1.1. HydroxylHydroxylHydroxylHydroxyl groupgroupgroupgroup—consists of a hydrogenhydrogenhydrogenhydrogen bonded to an oxygenoxygenoxygenoxygen 2.2.2.2. CarbonylCarbonylCarbonylCarbonyl groupgroupgroupgroup—a carboncarboncarboncarbon linked by a double bond to an oxygen atom 3.3.3.3. CarboxylCarboxylCarboxylCarboxyl groupgroupgroupgroup—consists of a carboncarboncarboncarbon bonded to a hydroxyl group hydroxyl group hydroxyl group hydroxyl group and double-bonded to an oxygenoxygenoxygenoxygen 4.4.4.4. AminoAminoAminoAmino groupgroupgroupgroup—composed of a nitrogennitrogennitrogennitrogen bonded to two two two two hydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeletonhydrogen atoms and a carbon skeleton 5.5.5.5. PhosphatePhosphatePhosphatePhosphate groupgroupgroupgroup—consists of a phosphorus atom bonded to four oxygen four oxygen four oxygen four oxygen atoms Copyright © 2009 Pearson Education, Inc.
  • المجاميع الوظيفية للمركبات العضوية أمثلة مجموعة ھيدروكسيل المجموعة الوظيفية كحول مجموعة كربونيل الدھايد كيتون مجموعة كاربوكسيل حمض كربوكسيلي حمض كربوكسيليحمض كربوكسيلي مؤين حمض كربوكسيلي مؤين مجموعة أمين أمين أمين مؤين مجموعة فوسفات (ATP)فوسفات عضوي ادينوسين مجموعة ميثيل مركب ميثيلي
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � There are four classes of biological molecules 1.1.1.1. CarbohydratesCarbohydratesCarbohydratesCarbohydratesاااا 2.2.2.2. ProteinsProteinsProteinsProteins 3.3.3.3. LipidsLipidsLipidsLipids 4.4.4.4. Nucleic acidsNucleic acidsNucleic acidsNucleic acids Copyright © 2009 Pearson Education, Inc.
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � The four classes of biological molecules contain very large molecules – They are often called macromoleculesmacromoleculesmacromoleculesmacromolecules because of their large size – They are also called polymerspolymerspolymerspolymers because they are made from identical building blocks strung together – The building blocks are called monomersmonomersmonomersmonomers Copyright © 2009 Pearson Education, Inc.
  • 3.3 Cells make a huge number of large molecules from a small set of small molecules � Monomers Monomers Monomers Monomers are linked together to form polymerspolymerspolymerspolymers through dehydration reactionsdehydration reactionsdehydration reactionsdehydration reactions, which remove water � Polymers are broken apart by hydrolysis,hydrolysis,hydrolysis,hydrolysis, the � Polymers are broken apart by hydrolysis,hydrolysis,hydrolysis,hydrolysis, the addition of water � All biological reactions of this sort are mediated by enzymes, which speed up chemical reactions in cells Copyright © 2009 Pearson Education, Inc.
  • Unlinked Monomer Short polymer Dehydration Dehydration reactions build a polymer chain Longer polymer Dehydration Reaction
  • Hydrolysis breaks a polymer chain Hydrolysis
  • CARBOHYDRATESCARBOHYDRATESCARBOHYDRATESCARBOHYDRATES Copyright © 2009 Pearson Education, Inc.
  • 3.4 Monosaccharides are the simplest carbohydrates السكريات ا2حادية ھي أبسط الكربوھيدرات � CarbohydratesCarbohydratesCarbohydratesCarbohydrates range from small sugar molecules (monomers) to large polysaccharides – Sugar monomers are monosaccharidesmonosaccharidesmonosaccharidesmonosaccharides, such as glucose glucose glucose glucose monosaccharidesmonosaccharidesmonosaccharidesmonosaccharides, such as glucose glucose glucose glucose and fructosefructosefructosefructose – These can be hooked together to form the polysaccharidespolysaccharidespolysaccharidespolysaccharides Copyright © 2009 Pearson Education, Inc.
  • 3.4 Monosaccharides are the simplest carbohydrates � The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides The carbon skeletons of monosaccharides vary in lengthvary in lengthvary in lengthvary in length – Glucose and fructose are six carbons long – Others have three to seven carbon atoms � Monosaccharides are the main fuels Monosaccharides are the main fuels Monosaccharides are the main fuels Monosaccharides are the main fuels (energy) (energy) (energy) (energy) for cellular for cellular for cellular for cellular workworkworkwork – Monosaccharides are also used as raw materials to manufacture other organic molecules Copyright © 2009 Pearson Education, Inc.
  • Structures of glucose and fructose Glucoseا (an aldose ) Fructose (a ketose )
  • Three representations of the ring form of glucose Structural Formula ا Abbreviated Structure Simplified Structure
  • 3.5 Cells link two single sugars to form disaccharides � Two monosaccharides (monomers) can bond to form a disaccharidedisaccharidedisaccharidedisaccharide in a dehydration reaction – An example is a glucoseglucoseglucoseglucose monomer – An example is a glucoseglucoseglucoseglucose monomer bonding to a fructosefructosefructosefructose monomer to form sucrosesucrosesucrosesucrose, a common disaccharide Copyright © 2009 Pearson Education, Inc.
  • Glucose Glucose Maltose Disaccharide formation by a dehydration reaction
  • 3.7 Polysaccharides are long chains of sugar units � StarchStarchStarchStarch is a storage polysaccharide composed of glucose monomers and found in plants � GlycogenGlycogenGlycogenGlycogen is a storage polysaccharide composed of glucose, which is hydrolyzed by animals when glucose is neededglucose is needed � CellulosCellulosCellulosCelluloseeee is a polymer of glucose that forms plant cell walls � ChitinChitinChitinChitin is a polysaccharide used by insects and crustaceans to build an exoskeleton Copyright © 2009 Pearson Education, Inc.
  • Starch granules in potato tuber cells Glycogen granules in muscle tissue Glucose Monomer GLYCOGEN STARCH Polysaccharides Cellulose fibrils in a plant cell wall Cellulose Molecules CELLULOSE Hydrogen bonds روابط ھيدروجينية
  • LIPIDS Copyright © 2009 Pearson Education, Inc. SteroidsPhospholipids True Fats
  • 3.8 Fats are lipids that are mostly energy-storage molecules � LipidsLipidsLipidsLipids are water insoluble (hydrophobichydrophobichydrophobichydrophobic, or water fearing) compounds that are important in energy storage – They contain twice as much energyenergyenergyenergy as a polysaccharide � FatsFatsFatsFats are lipids made from glycerol and fatty acids Copyright © 2009 Pearson Education, Inc.
  • 3.8 Fats are lipids that are mostly energy-storage molecules � Fatty acids link to glycerol by a Fatty acids link to glycerol by a Fatty acids link to glycerol by a Fatty acids link to glycerol by a dehydration reactiondehydration reactiondehydration reactiondehydration reaction – A fat contains one glycerol linked to three fatty acids – A fat contains one glycerol linked to three fatty acids – Fats are often called triglycerides because of their structure Copyright © 2009 Pearson Education, Inc.
  • Fatty acid Glycerol Fatty acid A dehydration reaction linking a fatty acid to glycerol
  • A fat molecule made from glycerol and three fatty acids
  • 3.8 Fats are lipids that are mostly energy-storage molecules � Some fatty acids contain double bondsSome fatty acids contain double bondsSome fatty acids contain double bondsSome fatty acids contain double bonds – This causes links or bends in the carbon chain because the maximum number of hydrogen atoms cannot bond to the carbons at the double bondbond – These compounds are called unsaturatedunsaturatedunsaturatedunsaturated fats fats fats fats because they have fewer than the maximum number of hydrogens – Fats with the maximum number of hydrogensare called saturated fatssaturated fatssaturated fatssaturated fats Copyright © 2009 Pearson Education, Inc.
  • 3.9 Phospholipids and steroids are important lipids with a variety of functions � PhospholipidsPhospholipidsPhospholipidsPhospholipids are structurally similar to fats and are an are structurally similar to fats and are an are structurally similar to fats and are an are structurally similar to fats and are an important component of all cellsimportant component of all cellsimportant component of all cellsimportant component of all cells 1. For example, they are a major part of cell membranes, in which they cluster into a bilayerof phospholipids 2. The hydrophilichydrophilichydrophilichydrophilic heads are in contact with the water of the environment and the internal part of the cell 3. The hydrophobichydrophobichydrophobichydrophobic tails band in the center of the bilayer Copyright © 2009 Pearson Education, Inc.
  • Water Hydrophobic Hydrophilic heads رؤس محبة للماء Section of a phospholipid membrane Cell external surface Hydrophobic tails ذيول كارھة للماء Water السطح الداخلي للخلية Cell internal surface
  • 3.9 Phospholipids and steroids are important lipids with a variety of functions � Steroids Steroids Steroids Steroids are lipids composed of fused ring are lipids composed of fused ring are lipids composed of fused ring are lipids composed of fused ring structuresstructuresstructuresstructures – CholesterolCholesterolCholesterolCholesterol is an example of a steroid that plays a significant role in steroid that plays a significant role in the structure of the cell membrane – In addition, cholesterol is the compound from which we synthesize sex hormones Copyright © 2009 Pearson Education, Inc.
  • PROTEINS Copyright © 2009 Pearson Education, Inc.
  • 3.11 Proteins are essential to the structures and functions of life � A proteinproteinproteinprotein is a polymer built from various combinations of 20 amino acid monomers – Proteins have unique structures that are directly related to their functionsare directly related to their functions – EnzymesEnzymesEnzymesEnzymes, proteins that serve as metabolic catalysts, regulate the chemical reactions within cells Copyright © 2009 Pearson Education, Inc.
  • 3.11 Proteins are essential to the structures and functions of life ا � Structural Structural Structural Structural proteins provide associations between body parts and contractilecontractilecontractilecontractile proteins are found within muscle � DefensiveDefensiveDefensiveDefensive proteins include antibodies of the � DefensiveDefensiveDefensiveDefensive proteins include antibodies of the immune system, and signalsignalsignalsignal proteins are best exemplified by the hormones � ReceptorReceptorReceptorReceptor proteins serve as antenna for outside signals, and transporttransporttransporttransport proteins carry oxygen Copyright © 2009 Pearson Education, Inc.
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acidsAmino acidsAmino acidsAmino acids, the building blocks of proteins, have an amino group and a carboxyl group – Both of these are covalently bonded covalently bonded covalently bonded covalently bonded to a – Both of these are covalently bonded covalently bonded covalently bonded covalently bonded to a central carbon atom – Also bonded to the central carbon is a hydrogen atom hydrogen atom hydrogen atom hydrogen atom and some other chemical chemical chemical chemical group symbolized by Rgroup symbolized by Rgroup symbolized by Rgroup symbolized by R Copyright © 2009 Pearson Education, Inc.
  • General structure of an amino acid Carboxyl group Amino Group م
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acids are classified as hydrophobic hydrophobic hydrophobic hydrophobic or hydrophilichydrophilichydrophilichydrophilic – Some amino acids have a nonpolar R group – Some amino acids have a nonpolar R group and are hydrophobichydrophobichydrophobichydrophobic – Others have a polar R a polar R a polar R a polar R group and are hydrophilichydrophilichydrophilichydrophilic, which means they easily dissolve in aqueous solutions Copyright © 2009 Pearson Education, Inc.
  • Examples of amino acids with hydrophobic and hydrophilic R groups Leucine (Leu) Hydrophobic Serine (Ser) ا Hydrophilic Aspartic acid (Asp)
  • 3.12 Proteins are made from amino acids linked by peptide bonds � Amino acid monomersmonomersmonomersmonomers are linked together to form polymericpolymericpolymericpolymeric proteins – This is accomplished by an enzymeenzymeenzymeenzyme----mediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reactionmediated dehydration reaction – This links the carboxyl group carboxyl group carboxyl group carboxyl group of one amino acid to the amino group amino group amino group amino group of the next amino acid – The covalentcovalentcovalentcovalent linkage resulting is called a peptide bonda peptide bonda peptide bonda peptide bond Copyright © 2009 Pearson Education, Inc.
  • Peptide bond Dehydration Reaction Peptide bond formation Carboxyl group Amino group Dipeptide ثنائي الببتيد Amino acid Amino acid
  • 3.13 A protein’s specific shape determines its function � A polypeptide chain contains hundreds or thousands of amino acids linked by peptide bonds – The amino acid sequence causes the – The amino acid sequence causes the polypeptide to assume a particular shape – The shape of a protein determines its specific function Copyright © 2009 Pearson Education, Inc.
  • Groove Space-filling model of lysozyme
  • 3.14 A protein’s shape depends on four levels of structure � A protein can have four levels of structure – Primary structurePrimary structurePrimary structurePrimary structure – Secondary structureSecondary structureSecondary structureSecondary structure – Secondary structureSecondary structureSecondary structureSecondary structure – Tertiary structureTertiary structureTertiary structureTertiary structure – Quaternary structureQuaternary structureQuaternary structureQuaternary structure Copyright © 2009 Pearson Education, Inc.
  • 3.14 A protein’s shape depends on four levels of structure � The primary structureprimary structureprimary structureprimary structure of a protein is its unique amino acid sequence – The correct amino acid sequence is determined by the cell’s genetic determined by the cell’s genetic information – The slightest change in this sequence affects the protein’s ability to function Copyright © 2009 Pearson Education, Inc.
  • Amino acids Primary structureأحماض أمينية التركيب ا7ولي
  • 3.14 A protein’s shape depends on four levels of structure � Protein secondary structuresecondary structuresecondary structuresecondary structure results from coiling or folding of the polypeptide – Coiling results in a helical structure called an alpha helixalpha helixalpha helixalpha helix – Folding may lead to a structure called a pleated sheetpleated sheetpleated sheetpleated sheet – Coiling and folding result from hydrogen bonding hydrogen bonding hydrogen bonding hydrogen bonding between certain areas of the polypeptide chain Copyright © 2009 Pearson Education, Inc.
  • Amino acids Hydrogen bond Alpha helix Secondary structure Pleated sheet
  • 3.14 A protein’s shape depends on four levels of structure � The overall three-dimensional shape of a protein is called its tertiary structuretertiary structuretertiary structuretertiary structure – Tertiary structure generally results from interactions between the R groups of the interactions between the R groups of the various amino acids – Disulfide bridges Disulfide bridges Disulfide bridges Disulfide bridges are covalentcovalentcovalentcovalent bonds that further strengthen the protein’s shape Copyright © 2009 Pearson Education, Inc.
  • Globular Polypeptide (single subunit(single subunit of transthyretin) Tertiary structure
  • 3.14 A protein’s shape depends on four levels of structure � Two or more polypeptide chains Two or more polypeptide chains Two or more polypeptide chains Two or more polypeptide chains (subunits) associate providing (subunits) associate providing (subunits) associate providing (subunits) associate providing quaternary quaternary quaternary quaternary structurestructurestructurestructure – Collagen is an example of a protein with quaternary structurewith quaternary structure – Its triple helix gives great strength to connective tissue, bone, tendons, and ligaments Copyright © 2009 Pearson Education, Inc.
  • PolypeptidePolypeptidePolypeptidePolypeptide chain (alpha helix)chain (alpha helix)chain (alpha helix)chain (alpha helix) Collagen is a fibrous protein with helical subunits Interwind into a larger triple helix, this Collagen fiberCollagen fiberCollagen fiberCollagen fiber helix, this arrangement gives the long fibers great strength Triple helix
  • Transthyretin, with four identical globular polypeptide subunits Quaternary structure Transthyretin: A plasma protein consisting of 127 amino acids that binds retinol and thyroxine
  • Four Levels of Protein Structure أربع مستويات من تركيب البروتين Primary structurePrimary structurePrimary structurePrimary structure Amino acids أحماض أمينية Hydrogen bond روابط ھيدروجينية Secondary structureSecondary structureSecondary structureSecondary structure Pleated sheet صحيفة مطوية Alpha helix حلزون ألفا Transthyretin, with four identical globular polypeptide subunits الترانسثيريتين بأربع من الوحدات الفرعية الكروية المتماثلة من متعدد البيبتيدات Quaternary structureQuaternary structureQuaternary structureQuaternary structure حلزون ألفاصحيفة مطوية Tertiary structureTertiary structureTertiary structureTertiary structure Globular Polypeptide (single subunit of transthyretin)
  • 3.13 A protein’s specific shape determines its function � If for some reason a protein’s shape is altered, it can no longer function – DenaturationDenaturationDenaturationDenaturation will cause polypeptide chains to unravel and lose their shape and, thus, their functionfunction – Proteins can be denatured by changes in salt salt salt salt concentration and pHconcentration and pHconcentration and pHconcentration and pH Copyright © 2009 Pearson Education, Inc.
  • NUCLEIC ACIDS Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � DNADNADNADNA (deoxyribonucleic aciddeoxyribonucleic aciddeoxyribonucleic aciddeoxyribonucleic acid) and RNARNARNARNA (ribonucleic ribonucleic ribonucleic ribonucleic acidacidacidacid) are composed of monomers called nucleotidesnucleotidesnucleotidesnucleotides – Nucleotides have three parts – A fiveA fiveA fiveA five----carbon sugar carbon sugar carbon sugar carbon sugar called ribose in RNA and deoxyribose in DNA – A phosphate groupA phosphate groupA phosphate groupA phosphate group – A nitrogenous base Copyright © 2009 Pearson Education, Inc.
  • Nitrogenous nucleotide, consisting of a phosphate group, sugar, and a nitrogenous base Phosphate Group Nitrogenous base (adenine) Sugar
  • Dehydration Short polymer Monomer Hydrolysis Longer polymer
  • Nucleotide Sugar-phosphate backbone Part of a polynucleotide
  • Base pair DNA double helix
  • � DNA nitrogenous bases are adenine (A), thymine (T), cytosine (C), and guanine (G) – RNA also has A, C, and G, but 3.16 Nucleic acids are information-rich polymers of nucleotides – RNA also has A, C, and G, but instead of T, it has uracil (U) Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � Two polynucleotide strands wrap around each other to form a DNA double helixdouble helixdouble helixdouble helix – The two strands are associated because particular bases always hydrogen bond to one anotherone another – A pairs with T, and C pairs with G, producing base pairsbase pairsbase pairsbase pairs � RNA is usually a single polynucleotide strand Copyright © 2009 Pearson Education, Inc.
  • 3.16 Nucleic acids are information-rich polymers of nucleotides � A particular nucleotide sequence that can instruct the formation of a polypeptide is called a genegenegenegene – Most DNA molecules consist of millions of base pairs and, consequently, many base pairs and, consequently, many genes – These genes, many of which are unique to the species, determine the structure of proteins and, thus, life’s structures and functions Copyright © 2009 Pearson Education, Inc.
  • 3.17 EVOLUTION CONNECTION: Lactose tolerance is a recent event in human evolution � Mutations Mutations Mutations Mutations are alterations in bases or the sequence of are alterations in bases or the sequence of are alterations in bases or the sequence of are alterations in bases or the sequence of bases in DNAbases in DNAbases in DNAbases in DNA � Lactose tolerance is the result of mutationsLactose tolerance is the result of mutationsLactose tolerance is the result of mutationsLactose tolerance is the result of mutations – In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization is turned off in adulthoodis turned off in adulthoodis turned off in adulthoodis turned off in adulthood – In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization In many people, the gene that dictates lactose utilization is turned off in adulthoodis turned off in adulthoodis turned off in adulthoodis turned off in adulthood – Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented Apparently, mutations occurred over time that prevented the gene from turning offthe gene from turning offthe gene from turning offthe gene from turning off – This is an excellent example of human evolutionThis is an excellent example of human evolutionThis is an excellent example of human evolutionThis is an excellent example of human evolution Copyright © 2009 Pearson Education, Inc.
  • You should now be able to ينبغي أن تكون قادراً ا;ن على فعل ما يلي 1. Discuss the importance of carbon to life’s molecular diversity ناقش أهمية الكربون في تنوع الجزيئات الحيوية. 1 2. Describe the chemical groups that are important to life صف المجاميع الكيميائية الهامة للحياة. 2 3. Explain how a cell can make a variety of large molecules from a small set of molecules اشرح كيفية تصنيع الخلية للعديد من الجزيئات الكبيرة من مجموعة صغيرة من . 3 الجزيئاتاشرح كيفية تصنيع الخلية للعديد من الجزيئات الكبيرة من مجموعة صغيرة من . 3 4. Define monosaccharides, disaccharides, and polysaccharides and explain their functions عرف السكاكر األحادية والثنائية والعديدة مع شرح وظائفها. 4 5. Define lipids, phospholipids, and steroids and explain their functions عرف اللبيدات والدهون الفسفورية واالسترويدات مع شرح وظائفها. 5 Copyright © 2009 Pearson Education, Inc.
  • You should now be able to ينبغي أن تكون قادراً ا;ن على فعل ما يلي 6. Describe the chemical structure of proteins and their importance to cells صف التركيب الكيميائي للبروتينات وأهميتها للخاليا. 6 7. Describe the chemical structure of nucleic acids and how they relate to inheritanceand how they relate to inheritance صف التركيب الكيميائي لألحماض النووية وعالقتها بالوراثة. 7 Copyright © 2009 Pearson Education, Inc.
  • Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Organic Compounds (Molecules) العضوية) الجزيئات(مدخل للمركبات Organic Compounds بالمركبات العضويةتسمى الجزيئات التي أساسھا ذرة الكربون Hydrocarbons يسمى كل من الميثان والمركبات المؤلفة من كربون وھيدروجين فقط بالھايدروكربونات Carbon Skeleton تسمسى سلسلة ذرات الكربون بالھيكل الكربوني Carbon Skeletons Can Be Branched Or Unbranched قد يتفرع الھيكل الكربوني أو 9 يتفرع Therefore, Different Compounds With The لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية Same Molecular Formula Can Be Produced لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية These Structures Are Called Isomers تعرف ھذه التراكيب بالنظائر Functional Group Affects A Biological Molecule’s Function In A Characteristic Way تؤثر المجموعة الوظيفية في وظيفة الجزيئ الحيوي بطريقة مميزة Hydrophilic (Water-Loving) المركبات المحتوية على مجاميع وظيفية تكون محبة للماء This Means That They Are Soluble In Water, Which Is A Necessary Prerequisite For Their Roles In Water-Based Life يعني ھذا أنھا تذوب في الماء وھذا متطلب ضروري للقيام بوظائفھا الحيوية المعتمدة على الماء Hydroxyl Group—Consists Of A Hydrogen Bonded To An Oxygen تتكون من ھيدروجين مرتبط بأوكسجين–الھيدروكسيلمجموعة
  • Carbonyl Group—A Carbon Linked By A Double Bond To An Oxygen Atom كربون متصل بذرة أوكسجين برابطة ثنائية–الكربونيلمجموعة Carboxyl Group—Consists Of A Carbon Bonded To A Hydroxyl Group And Double- Bonded To An Oxygen تتألف من كربون مرتبط بمجموعة –كربوكسيلمجموعة كما وترتبط برابطة ثنائية باRوكسجين الھيدروكسيل Amino Group—Composed Of A Nitrogen Bonded To Two Hydrogen Atoms And A Carbon Skeleton مكونة من نيتروجين مرتبط بذرتي ھيدروجين –مجموعة أمين وھيكل كربوني Phosphate Group—Consists Of A Phosphorus تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Phosphate Group—Consists Of A Phosphorus Atom Bonded To Four Oxygen Atoms تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات أوكسجين Biological Molecules ھناك أربعة أصناف من الجزيئات الحيوية Carbohydrates الكربوھيدرات Proteins البروتينات Lipids الدھون(اللبيدات( Nucleic Acids حماض النوويةRا Macromolecules Because Of Their Large Size تسمى عادة بالجزيئات الكبيرة لحجمھا الكبير They Are Made From Identical Building Blocks Strung Together Rنھا مكونة من وحدات بنائية متماثلة بالبوليميراتتسمى أيضاً متماسكة بقوة
  • The Building Blocks Are Called Monomers بالمونيميراتتسمى وحدات البناء Dehydration Reactions, Which Remove Water بتفاعYت نزع الماء بوليميراتلتكون ببعضھا المونيميراتترتبط Polymers Are Broken Apart By Hydrolysis, The Addition Of Water )بإضافة الماء( الحلمأةأو بالتميؤ البوليميراتتنحل All Biological Reactions Of This Sort Are Mediated By Enzymes, Which Speed Up Chemical Reactions In Cells كل ھذه العمليات الحيوية من ھذا النوع تتوسط فيھا ا]نزيمات التي تسرع من التفاعYت الكيميائية في الخYيا Dehydration Reaction تفاعل نزع الماء Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Dehydration Reaction تفاعل نزع الماء Hydrolysis الحلمأةأو التميؤ Monosaccharides, Such As Glucose And Fructose سكر مثل الجلوكوز مونيميراتالسكريات اRحادية عبارة عن والفركتوز Disaccharide In A Dehydration Reaction البعض ليكونا ببعضھما) مونيمران(يمكن أن يرتبط سكران أحاديان سكراً ثنائياً بتفاعل نزع الماء An Example Is A Glucose Monomer Bonding To A Fructose Monomer To Form Sucrose, A Common Disaccharide لتكوين الفركتوز بمونيمرالجلوكوز مونيمر إرتباطمثال ذلك ھو )سكر ثنائي شائع( السكروز
  • Starch Is A Storage Polysaccharide Composed Of Glucose Monomers And Found In Plants جلوكوز مونيميراتتخزيني ويتكون من سكرمتعددالنشا عبارة عن ويوجد في النبات Glycogen Is A Storage Polysaccharide Composed Of Glucose, Which Is Hydrolyzed By Animals When Glucose Is Needed تخزيني ويتكون من سكرمتعددعن الحيوانيعبارةأو النشا الجYيكوجين عند الحاجة إلى الجلوكوز الجYيكوجينالجلوكوز ، وتحلل الحيوانات Cellulose Is A Polymer Of Glucose That Forms Plant Cell Walls جلوكوزي يكون جدر الخYيا في النباتات بوليميرعبارة عن السيليلوز Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Forms Plant Cell Walls Chitin Is A Polysaccharide Used By Insects And Crustaceans To Build An Exoskeleton عبارة عن سكر متعدد تستخدمه الحشرات والقشريات لبناء الكايتين ھياكلھا الخارجية Lipids Are Water Insoluble (Hydrophobic, Or Water Fearing) Compounds That Are Important In Energy Storage ، وھي ھامة في ) كارھة للماء(ھي مركبات 9 تذوب في الماء اللبيدات تخزين الطاقة They Contain Twice As Much Energy As A Polysaccharide المتعددة السكاكرتحتوي على ضعف الطاقة الموجودة في Fats Are Lipids Made From Glycerol And Fatty Acids نوع من اللبيدات مكونة من ) السمن والزبدة والزيت(الدھون جليسيرول وأحماض دھنية Unsaturated Fats Because They Have Fewer Than The Maximum Number Of Hydrogens تسمى ھذه المركبات بالدھون غير المشبعة Rنھا تحتوى على عدد أقل من العدد الكلي للھيدروجين
  • Fats With The Maximum Number Of Hydrogens Are Called Saturated Fats تسمى الدھون المحتوية على العدد الكلي للھيدروجين بالدھون المشبعة )الكربون ذراتروابط ثنائية بين بھا9 يوجد ( Phospholipids Are Structurally Similar To Fats And Are An Important Component Of All Cells الفسفورية الدھون في تركيبھا وھي من المكونات اللبيداتتشابه اRساسية للخلية For Example, They Are A Major Part Of Cell Membranes, In Which They Cluster Into A Bilayer Of Phospholipids على سبيل المثال ھي مكون ھام لhغشية الخلوية حيث تتجمع على ھيئة طبقتين من الدھون الفسفورية Steroids Are Lipids Composed Of Fused Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Steroids Are Lipids Composed Of Fused Ring Structures عبارة عن دھون مكونة من حلقات تركيبية متداخلة اRسترويدات Cholesterol Is An Example Of A Steroid That Plays A Significant Role In The Structure Of The Cell Membrane التي تلعب دوراً ھاماً في تركيب لYسترويداتھو مثال الكوليسترول غشاء الخلية In Addition, Cholesterol Is The Compound From Which We Synthesize Sex Hormones ھرموناتنا بهھو المركب الذي نبني الكوليسترولبا]ضافة لذلك فإن الجنسية Anabolic Steroids Are Synthetic Variants Of Testosterone That Can Cause A Buildup Of Muscle And Bone Mass البنائي عبارة عن توليفة صناعية من اRيض سترويدات والتي تؤدي لبناء الكتلة العضلية ) الذكورة ھرمونات( التيستيسترونات والعظمية Protein Is A Polymer Built From Various Combinations Of 20 Amino Acid Monomers مونيمراتمن 20يبنى من توافيق بين بوليمرالبروتين عبارة عن اRمينيةاRحماض
  • Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Organic Compounds (Molecules) العضوية) الجزيئات(مدخل للمركبات Organic Compounds بالمركبات العضويةتسمى الجزيئات التي أساسھا ذرة الكربون Hydrocarbons يسمى كل من الميثان والمركبات المؤلفة من كربون وھيدروجين فقط بالھايدروكربونات Carbon Skeleton تسمسى سلسلة ذرات الكربون بالھيكل الكربوني Carbon Skeletons Can Be Branched Or Unbranched قد يتفرع الھيكل الكربوني أو 9 يتفرع Therefore, Different Compounds With The لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية Same Molecular Formula Can Be Produced لذلك يمكن إنتاج مركبات مختلفة بنفس الصيغة الجزيئية These Structures Are Called Isomers تعرف ھذه التراكيب بالنظائر Functional Group Affects A Biological Molecule’s Function In A Characteristic Way تؤثر المجموعة الوظيفية في وظيفة الجزيئ الحيوي بطريقة مميزة Hydrophilic (Water-Loving) المركبات المحتوية على مجاميع وظيفية تكون محبة للماء This Means That They Are Soluble In Water, Which Is A Necessary Prerequisite For Their Roles In Water-Based Life يعني ھذا أنھا تذوب في الماء وھذا متطلب ضروري للقيام بوظائفھا الحيوية المعتمدة على الماء Hydroxyl Group—Consists Of A Hydrogen Bonded To An Oxygen تتكون من ھيدروجين مرتبط بأوكسجين–الھيدروكسيلمجموعة
  • Carbonyl Group—A Carbon Linked By A Double Bond To An Oxygen Atom كربون متصل بذرة أوكسجين برابطة ثنائية–الكربونيلمجموعة Carboxyl Group—Consists Of A Carbon Bonded To A Hydroxyl Group And Double- Bonded To An Oxygen تتألف من كربون مرتبط بمجموعة –كربوكسيلمجموعة كما وترتبط برابطة ثنائية باRوكسجين الھيدروكسيل Amino Group—Composed Of A Nitrogen Bonded To Two Hydrogen Atoms And A Carbon Skeleton مكونة من نيتروجين مرتبط بذرتي ھيدروجين –مجموعة أمين وھيكل كربوني Phosphate Group—Consists Of A Phosphorus تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Phosphate Group—Consists Of A Phosphorus Atom Bonded To Four Oxygen Atoms تتكون من ذرة فوسفور مرتبطة بأربعة ذرات –مجموعة فوسفات أوكسجين Biological Molecules ھناك أربعة أصناف من الجزيئات الحيوية Carbohydrates الكربوھيدرات Proteins البروتينات Lipids الدھون(اللبيدات( Nucleic Acids حماض النوويةRا Macromolecules Because Of Their Large Size تسمى عادة بالجزيئات الكبيرة لحجمھا الكبير They Are Made From Identical Building Blocks Strung Together Rنھا مكونة من وحدات بنائية متماثلة بالبوليميراتتسمى أيضاً متماسكة بقوة
  • The Building Blocks Are Called Monomers بالمونيميراتتسمى وحدات البناء Dehydration Reactions, Which Remove Water بتفاعYت نزع الماء بوليميراتلتكون ببعضھا المونيميراتترتبط Polymers Are Broken Apart By Hydrolysis, The Addition Of Water )بإضافة الماء( الحلمأةأو بالتميؤ البوليميراتتنحل All Biological Reactions Of This Sort Are Mediated By Enzymes, Which Speed Up Chemical Reactions In Cells كل ھذه العمليات الحيوية من ھذا النوع تتوسط فيھا ا]نزيمات التي تسرع من التفاعYت الكيميائية في الخYيا Dehydration Reaction تفاعل نزع الماء Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Dehydration Reaction تفاعل نزع الماء Hydrolysis الحلمأةأو التميؤ Monosaccharides, Such As Glucose And Fructose سكر مثل الجلوكوز مونيميراتالسكريات اRحادية عبارة عن والفركتوز Disaccharide In A Dehydration Reaction البعض ليكونا ببعضھما) مونيمران(يمكن أن يرتبط سكران أحاديان سكراً ثنائياً بتفاعل نزع الماء An Example Is A Glucose Monomer Bonding To A Fructose Monomer To Form Sucrose, A Common Disaccharide لتكوين الفركتوز بمونيمرالجلوكوز مونيمر إرتباطمثال ذلك ھو )سكر ثنائي شائع( السكروز
  • Starch Is A Storage Polysaccharide Composed Of Glucose Monomers And Found In Plants جلوكوز مونيميراتتخزيني ويتكون من سكرمتعددالنشا عبارة عن ويوجد في النبات Glycogen Is A Storage Polysaccharide Composed Of Glucose, Which Is Hydrolyzed By Animals When Glucose Is Needed تخزيني ويتكون من سكرمتعددعن الحيوانيعبارةأو النشا الجYيكوجين عند الحاجة إلى الجلوكوز الجYيكوجينالجلوكوز ، وتحلل الحيوانات Cellulose Is A Polymer Of Glucose That Forms Plant Cell Walls جلوكوزي يكون جدر الخYيا في النباتات بوليميرعبارة عن السيليلوز Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Forms Plant Cell Walls Chitin Is A Polysaccharide Used By Insects And Crustaceans To Build An Exoskeleton عبارة عن سكر متعدد تستخدمه الحشرات والقشريات لبناء الكايتين ھياكلھا الخارجية Lipids Are Water Insoluble (Hydrophobic, Or Water Fearing) Compounds That Are Important In Energy Storage ، وھي ھامة في ) كارھة للماء(ھي مركبات 9 تذوب في الماء اللبيدات تخزين الطاقة They Contain Twice As Much Energy As A Polysaccharide المتعددة السكاكرتحتوي على ضعف الطاقة الموجودة في Fats Are Lipids Made From Glycerol And Fatty Acids نوع من اللبيدات مكونة من ) السمن والزبدة والزيت(الدھون جليسيرول وأحماض دھنية Unsaturated Fats Because They Have Fewer Than The Maximum Number Of Hydrogens تسمى ھذه المركبات بالدھون غير المشبعة Rنھا تحتوى على عدد أقل من العدد الكلي للھيدروجين
  • Fats With The Maximum Number Of Hydrogens Are Called Saturated Fats تسمى الدھون المحتوية على العدد الكلي للھيدروجين بالدھون المشبعة )الكربون ذراتروابط ثنائية بين بھا9 يوجد ( Phospholipids Are Structurally Similar To Fats And Are An Important Component Of All Cells الفسفورية الدھون في تركيبھا وھي من المكونات اللبيداتتشابه اRساسية للخلية For Example, They Are A Major Part Of Cell Membranes, In Which They Cluster Into A Bilayer Of Phospholipids على سبيل المثال ھي مكون ھام لhغشية الخلوية حيث تتجمع على ھيئة طبقتين من الدھون الفسفورية Steroids Are Lipids Composed Of Fused Chapt. 3: The Molecules Of Cells الجزيئات الخلوية تعريف المصطلـــــح المصطلــــــــــــــح Steroids Are Lipids Composed Of Fused Ring Structures عبارة عن دھون مكونة من حلقات تركيبية متداخلة اRسترويدات Cholesterol Is An Example Of A Steroid That Plays A Significant Role In The Structure Of The Cell Membrane التي تلعب دوراً ھاماً في تركيب لYسترويداتھو مثال الكوليسترول غشاء الخلية In Addition, Cholesterol Is The Compound From Which We Synthesize Sex Hormones ھرموناتنا بهھو المركب الذي نبني الكوليسترولبا]ضافة لذلك فإن الجنسية Anabolic Steroids Are Synthetic Variants Of Testosterone That Can Cause A Buildup Of Muscle And Bone Mass البنائي عبارة عن توليفة صناعية من اRيض سترويدات والتي تؤدي لبناء الكتلة العضلية ) الذكورة ھرمونات( التيستيسترونات والعظمية Protein Is A Polymer Built From Various Combinations Of 20 Amino Acid Monomers مونيمراتمن 20يبنى من توافيق بين بوليمرالبروتين عبارة عن اRمينيةاRحماض
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